The present invention relates generally to an electrolytic antiseptic device and, in particular, to an electrolytic therapeutic device comprising a silver-bearing material and at least one metal other than silver, e.g., zinc. The invention also pertains to an antiseptic and therapeutic method of treating tissue through the use of a silver-bearing material and a metal other than silver.
The art of applying a low voltage electric current to control microbes and promote healing action for medical and hygienic purposes has been developing for many years. In particular, it is known that the use of a low voltage electric field applied through a reservoir can be used to deliver drugs or agents in the reservoir systematically or to produce a localized therapeutic effect. Moreover, the application of electricity to the body, with or without drugs or agents, can be used therapeutically. Direct current fields can exert a microbicidal effect, and electric voltage can also via electrophoresis induce agents or medications to penetrate tissue more deeply, and can induce the agents to penetrate structures on implants such as biofilms. Further therapeutic effects of electricity include control of pain, edema and acceleration of wound healing. Moreover, the localized effect of drugs and agents can be greater at the delivery site than the effect that is seen with topically or systematically delivered agents alone, due to higher available concentrations at the site, over time.
Such low voltage antibacterial devices are able to infuse charged molecules, i.e., iontophoresis, as well as uncharged molecules into the body, i.e., electro-osmosis. For example, U.S. Pat. No. 5,298,017 to Theeuwes et al. (xe2x80x9cthe ""017 patent), which is incorporated herein by reference, describes a iontophoretic process by which drugs are delivered transdermally or transmucosally under the influence of an electrical potential. lontophoretic devices use two distinct electrodes, with at least one of the electrodes being applied to the body. These devices typically utilize a conventional electric power source, such as a battery, to develop the electric current. In some cases, the power source is located separately from the device and in some cases the power source is integrated into the device. These devices also rely solely on the creation of a discrete ion pathway incorporating the body or tissue to effect an electromotive force via forms defined by the sequence of a first electrode, tissue and a second electrode.
There are devices described in the prior art that rely on the electric field generated by the device itself. The power source generally provides no therapeutic value itself other than to provide the electric current necessary to drive the iontophoretic or electro-osmotic device to deliver an agent that is different from the electrode metals. Further, if the power supply should fail for any reason, the device is typically rendered useless. Also, where the power source located away from the device, limitations are imposed on patient mobility. Still further, even when the prior art integrates the conventional power source into the device there are limitations. In particular, the prior art makes it clear that the conventional power source must be protected from short circuiting itself. Consequently, great lengths have been taken to insure that the two electrodes are insulated in order to limit the possibility of a short circuit. Further limitations of these devices include high cost due to wires, electrical insulation, battery failure, problems with user compliance, maintenance, and damage.
In spite of the fact that the use of external power sources is prevalent in the art of iontophoresis and electro-osmosis, it is known to rely exclusively on the electric potential generated by the galvanic couple between dissimilar materials, e.g., a zinc electrode and a silver/silver chloride counter electrode, to deliver a drug. For example, the embodiment of the device illustrated in FIG. 2 of the ""017 patent does not use an external power source. While the primary purpose of such devices is to deliver a drug present in a drug reservoir, as a consequence of the galvanic couple ions of the material used for the anode and/or cathode are delivered into the body. Unfortunately, because the anode and cathodes of such prior art devices are typically made from materials having a relatively low total surface area, the rate of metallic ion transfer from the metallic electrodes is typically lower than desired for satisfactory therapeutic effects.
As described in U.S. Pat. No. 5,814,094 to Becker et al. (xe2x80x9cthe ""094 patentxe2x80x9d), iontophoretic devices that provide silver ions for wound healing are known. Use of silver-coated nylon as the anode for the iontophoretic device of the device of the ""094 patent provides a relatively high total surface area material as the source of silver ions. However, the device of the ""094 patent features the use of an external power source connected to the silver-coated nylon anode to generate the electrical potential that drives the silver ions into the body, and so suffers from the limitations of other iontophoretic devices described above. In view of the foregoing, there is an apparent need for low cost, simple, robust, flexible, user compliant electrolytic apparatus that offers the benefits of the prior art and offers additional uses.
One aspect of the present invention is an electrolytic device that comprises a structure having a first surface with a first surface area, a thickness region and a plurality of openings in the thickness region. The plurality of openings is defined by a plurality of inner surfaces that together have an inner surface area, with the plurality of inner surfaces comprising silver. The device also includes a metal-bearing material other than silver that is interspersed throughout at least some of the plurality of openings.
Another aspect of the present invention is an electrolytic device that comprises a structure having a first surface with a first surface area, a thickness region and a plurality of openings in the thickness region. The plurality of openings is defined by a plurality of inner surfaces that together have an inner surface area, with the first surface and the plurality of inner surfaces comprising silver. The device also includes a metal-bearing material other than silver that contacts the first surface.
Still another aspect of the present invention is an electrolytic device that comprises a first region having a structure having a first surface with a first surface area, a thickness region and a plurality of openings in the thickness region. The plurality of openings is defined by a plurality of inner surfaces that together have an inner surface area, with the plurality of inner surfaces comprising silver. The device also includes a second region comprising a metal-bearing material other than silver. The second region does not touch the first region.
Yet another aspect of the present invention is a method of administering silver and a metal other than silver to a body. The first step of the method involves providing a porous silver-bearing structure and a metal-bearing material other than silver proximate said structure. Next, the porous silver-bearing structure and the metal-bearing material other than silver is applied to the body so that at least the structure contacts the body and so that no voltage source is connected to the structure and the metal-bearing material. Finally, before or after the preceding step, moisture is added to the structure and the metal-bearing material other than silver.